An IR-reflectivity and X-ray diffraction study of high energy He-ion implantation-induced damage in 4H–SiC

Abstract

Due to recent progress in silicon carbide (SiC) technology, understanding the behaviour of defects in SiC is a crucial challenge for the industrial development of SiC-based devices. High energy helium ion implantation at high fluence in SiC creates a few microns deep damaged layers with nanocavities which are expected to play an important role in gettering of unwanted impurities. Post-implantation evolution of the ion implantation-induced damage is then controlled by thermal annealing. Results of an infrared reflectivity (IRR) and X-ray diffraction (XRD) study of ion implantation-induced damage in crystalline (0 0 0 1) n-type 4H–SiC implanted at room temperature with 1.6 MeV He + ions at the fluence of 10 17 cm −2 show the formation of two layers above the unperturbed crystal: a 3.4 μm deep defective strained surface layer on a 0.4 μm thick strongly perturbed interface layer. Thermal annealing at 1500 °C for 30 min under high vacuum was shown to induce structural recovery of the surface layer.